1. Field of the Invention
The present invention relates to a hybrid blade for turbomachines such as static gas turbines or aircraft engines, the blade comprising an outer shell and an inner core, which is at least partially enclosed by the outer shell. The invention furthermore relates to a production method for such a blade.
2. Discussion of Background Information
Turbomachines, such as static gas turbines or aircraft engines, comprise a multiplicity of rotor blades and guide vanes which interact with the flowing fluid, such as air and combustion gases. The guide vanes and rotor blades are in this case exposed to high temperatures, aggressive media and high pressures. In addition, erosion and impact stresses may occur because of extraneous substances and objects entering the turbomachine. The rotor blades must further more absorb high centrifugal forces due to the high speeds at which they are rotated, with the result that blades of turbomachines have to satisfy a complex requirement profile in terms of strength, high-temperature stability, oxidation and corrosion resistance, impact strength, etc. At the same time, however, the density, in particular of the rotor blades, should be low in order to keep centrifugal forces low and to keep the masses to be accelerated low, or in aircraft engines to make a lower weight of the turbomachine possible overall.
Although a multiplicity of corresponding blades made of different materials are already known, because of the complex requirement profile there is a further need for corresponding optimization in order to be able to provide blades having a suitable property profile. For example, US 2011/0 229 337 A1, the entire disclosure of which is incorporated by reference herein, discloses a ceramic hybrid blade which comprises an outer shell region and an inner core region, the outer shell region being formed from an SiC/SiC material while the inner core region is formed from an Si/SiC composite material and a monolithic ceramic material.
In view of the foregoing, it would be advantageous to have available a blade for a turbomachine, which in particular has an optimized property profile for use in aircraft engines and, preferably with a low density, good corrosion and oxidation resistance and a high strength, in particular impact and shear strength. Also, the corresponding blade should be straightforwardly producible and reliably usable.